strLgrkPower {factorial2x2} | R Documentation |
Computes the power for the overall treatment A effect based on the stratified logrank test based on Slud (1994).
strLgrkPower(n, hrA, hrB, hrAB, avgprob, dig = 2, alpha = 0.05)
n |
total subjects with n/4 subjects in the C, A, B, and AB groups |
hrA |
group A to group C hazard ratio |
hrB |
group B to group C hazard ratio |
hrAB |
group AB to group C hazard ratio |
avgprob |
average event probability across the four groups as calculated by the function eventProb |
dig |
number of decimal places to which we |
alpha |
two-sided significance level |
The roundDown
function is used in conjunction with the dig
argument
to insure that any rounding of the (negative) critical values will be done conservatively to control
the familywise type I error at the desired level.
mean |
logrank mean value |
power |
logrank power |
nevent |
expected number of events |
Eric Leifer, James Troendle
Leifer, E.S., Troendle, J.F., Kolecki, A., Follmann, D. Joint testing of overall and simple effect for the two-by-two factorial design. (2019). Submitted.
Slud, E.V. Analysis of factorial survival experiments. Biometrics. 1994; 50: 25-38.
rateC <- 0.0445 hrA <- 0.80 hrB <- 0.80 hrAB <- 0.72 mincens <- 4.0 maxcens <- 8.4 avgprob <- eventProb(rateC, hrA, hrB, hrAB, mincens, maxcens)$avgprob n <- 4600 strLgrkPower(n, hrA, hrB, hrAB, avgprob, dig = 2, alpha = 0.05) # $mean # [1] -2.537779 # $power # [1] 0.7182932 # $nevent # [1] 954.8738